package scjp;

public class Redwood extends Tree {
	public static void main(String[] args) {
		new Redwood().go();
	}

	void go() {
		go2(new Tree(), new Redwood());
		go2((Redwood) new Tree(), new Redwood());
	}

	void go2(Tree t1, Redwood r1) {
		if(t1!=null && t1 instanceof Redwood){Redwood r2 = (Redwood) t1;}
		Tree t2 = (Tree) r1;
	}
}

class Tree {
}
